C/2021 F1 (Lemmon-PANSTARRS)
ephemeris	date	magn	radius	delta	ra	dec	elong	phase	PA
Nearest approach	12 Feb 2022	10.9	1.336 AU	1.416 AU	20h29m	+48°54'	64.7°	41.9°	340°
Perihelion	6 Apr 2022	9.6	1.000 AU	1.904 AU	01h06m	+24°18'	17.8°	17.8°	5°
Today	17 Feb 2026	30.3	12.848 AU	12.867 AU	13h16m	-76°56'	86.7°	4.4°	313°

The interactive orbit chart above shows the comet's path through the solar system and its position at the given date. Green and blue lines are shown perpendicular to the ecliptic plane: Green if the path is above the ecliptic plane, blue if it is below. (Left-click and drag to rotate the view; Right-click and drag to move the view; Use scroll wheel to zoom in our out.)

Light curve

The light curve chart below shows the estimated development of the comet's magnitude. Blue and black dots are visual and photometric CCD observations from COBS. This lightcurve is being recalculated every 6 hours based on the available COBS/MPC observations (currently 8.3 + 5 log[∆] + 14.9 log[r]). An additional green curve is displayed when an increase in apparent brightness is expected due to forward scattering of sunlight, which occurs when a dust-rich comet is located between the Earth and the Sun. (See Marcus 2007)

Charts

The all-sky chart below shows the path of the comet over the same period as the light curve. The comet's current position is marked yellow.

The following chart shows the short-term path of the comet in a field of view that is optimized for (~10x50) binoculars and finderscopes.

Orbital elements

The orbital elements of C/2021 F1 (Lemmon-PANSTARRS) are:

    e (Eccentricity)                : 0.9959980
    q (Perihelion distance)         : 0.9995700
    i (Inclination)                 : 107.27710
    Ω (Longitude of ascending node) : 203.58210
    ω (Argument of perihelion)      : 146.96330
    L (Longitude of perihelion)     : 214.51362
    B (Latitude of perihelion)      : 31.37100
    T (Time of perihelion passage)  : 2459676.25180
    P (Orbital period in years)     : 3947.34

    Epoch                           : 2025 Nov 12
    Reference                       : MPEC 2022-QD9

    Classification(s):              : Nearly isotropic; Returning (a < 10000 AU); External (P > 200 years)

Ephemerides

Date       Time       RA (2000)    DEC (2000)    delta   radius  elong  phase   PA    magn
2026-02-16 00:00 UT   13 17 29.8   -76 53 23    12.870   12.840   86.0    4.4   311   30.3 
2026-02-17 00:00 UT   13 16 44.0   -76 55 56    12.868   12.846   86.5    4.4   312   30.3 
2026-02-17 06:32 UT   13 16 31.3   -76 56 37    12.867   12.848   86.7    4.4   313   30.3 
2026-02-18 00:00 UT   13 15 56.9   -76 58 25    12.865   12.852   87.0    4.4   313   30.3 
2026-02-19 00:00 UT   13 15 08.4   -77 00 50    12.863   12.859   87.5    4.4   314   30.3 
2026-02-20 00:00 UT   13 14 18.6   -77 03 12    12.860   12.865   88.1    4.4   316   30.3 
2026-02-21 00:00 UT   13 13 27.4   -77 05 29    12.858   12.872   88.6    4.4   317   30.3 
2026-02-22 00:00 UT   13 12 34.9   -77 07 42    12.856   12.878   89.1    4.4   318   30.3 
2026-02-23 00:00 UT   13 11 41.2   -77 09 51    12.853   12.885   89.6    4.4   319   30.3 
2026-02-24 00:00 UT   13 10 46.1   -77 11 56    12.851   12.891   90.1    4.4   320   30.3 
2026-02-25 00:00 UT   13 09 49.9   -77 13 56    12.849   12.897   90.6    4.4   321   30.3 
2026-02-26 00:00 UT   13 08 52.4   -77 15 52    12.846   12.904   91.1    4.4   322   30.3 
2026-02-27 00:00 UT   13 07 53.7   -77 17 43    12.844   12.910   91.6    4.4   323   30.3 

    Terminology:
            
    delta:  distance between comet and earth in AU
    radius: distance between comet and sun in AU
    magn:   magnitude (brightness) estimate    
    ra:     right ascension in hours (24h = 360deg)
    dec:    declination in degrees
    elong:  elongation in degrees (angle sun-earth-comet)    
    phase:  phase angle in degrees (angle sun-comet-earth)        
    AU:     Astronomical Unit (mean distance between earth and sun: 149597870.7 km      
    

Orbital elements usually provided by the MPC (Minor Planet Center).
Observations contributed by observers worldwide, via COBS (Comet Observation Database) or the MPC (Minor Planet Center)
Calculations by a modified version of AAPlus, a C# implementation of the AA+ project by PJ Naughter from the algorithms presented in the book "Astronomical Algorithms" by Jean Meeus.
NGC2000 dso catalog and star labels from VizieR as provided by the Strasbourg astronomical Data Center.
Tycho2 catalog from the ESO archive.